C++ (Cpp) CountOGRVRTLayers示例

示例#1

文件： ogrvrtdatasource.cpp 项目： 0004c/node-gdal

static int CountOGRVRTLayers(CPLXMLNode *psTree)
{
    if( psTree->eType != CXT_Element )
        return 0;

    int nCount = 0;
    if( EQUAL(psTree->pszValue, "OGRVRTLayer") )
        nCount ++;

    CPLXMLNode* psNode;
    for( psNode=psTree->psChild; psNode != NULL; psNode=psNode->psNext )
    {
        nCount += CountOGRVRTLayers(psNode);
    }

    return nCount;
}

示例#2

文件： ogrvrtdatasource.cpp 项目： 0004c/node-gdal

int OGRVRTDataSource::Initialize( CPLXMLNode *psTree, const char *pszNewName,
                                  int bUpdate )

{
    CPLAssert( nLayers == 0 );

    this->psTree = psTree;

/* -------------------------------------------------------------------- */
/*      Set name, and capture the directory path so we can use it       */
/*      for relative datasources.                                       */
/* -------------------------------------------------------------------- */
    CPLString osVRTDirectory = CPLGetPath( pszNewName );

    pszName = CPLStrdup( pszNewName );

/* -------------------------------------------------------------------- */
/*      Look for the OGRVRTDataSource node, it might be after an        */
/*      <xml> node.                                                     */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psVRTDSXML = CPLGetXMLNode( psTree, "=OGRVRTDataSource" );
    if( psVRTDSXML == NULL )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Did not find the <OGRVRTDataSource> node in the root of the document,\n"
                  "this is not really an OGR VRT." );
        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      Determine if we must proxy layers.                              */
/* -------------------------------------------------------------------- */
    int nOGRVRTLayerCount = CountOGRVRTLayers(psVRTDSXML);

    int nMaxSimultaneouslyOpened = atoi(CPLGetConfigOption("OGR_VRT_MAX_OPENED", "100"));
    if( nMaxSimultaneouslyOpened < 1 )
        nMaxSimultaneouslyOpened = 1;
    if( nOGRVRTLayerCount > nMaxSimultaneouslyOpened )
        poLayerPool = new OGRLayerPool(nMaxSimultaneouslyOpened);

/* -------------------------------------------------------------------- */
/*      Look for layers.                                                */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psLTree;

    for( psLTree=psVRTDSXML->psChild; psLTree != NULL; psLTree=psLTree->psNext )
    {
        if( psLTree->eType != CXT_Element )
            continue;

/* -------------------------------------------------------------------- */
/*      Create the layer object.                                        */
/* -------------------------------------------------------------------- */
        OGRLayer  *poLayer = InstanciateLayer(psLTree, osVRTDirectory, bUpdate);
        if( poLayer == NULL )
            continue;

/* -------------------------------------------------------------------- */
/*      Add layer to data source layer list.                            */
/* -------------------------------------------------------------------- */
        papoLayers = (OGRLayer **)
            CPLRealloc( papoLayers,  sizeof(OGRLayer *) * (nLayers+1) );
        papoLayers[nLayers++] = poLayer;
    }

    return TRUE;
}

示例#3

文件： ogrvrtdatasource.cpp 项目： OSGeo/gdal

bool OGRVRTDataSource::Initialize( CPLXMLNode *psTreeIn, const char *pszNewName,
                                   int bUpdate )

{
    CPLAssert(nLayers == 0);

    AddForbiddenNames(pszNewName);

    psTree = psTreeIn;

    // Set name, and capture the directory path so we can use it
    // for relative datasources.
    CPLString osVRTDirectory = CPLGetPath(pszNewName);

    pszName = CPLStrdup(pszNewName);

    // Look for the OGRVRTDataSource node, it might be after an <xml> node.
    CPLXMLNode *psVRTDSXML = CPLGetXMLNode(psTree, "=OGRVRTDataSource");
    if( psVRTDSXML == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Did not find the <OGRVRTDataSource> node in the root of the "
                 "document, this is not really an OGR VRT.");
        return false;
    }

    // Determine if we must proxy layers.
    const int nOGRVRTLayerCount = CountOGRVRTLayers(psVRTDSXML);

    const int nMaxSimultaneouslyOpened =
      std::max(atoi(CPLGetConfigOption("OGR_VRT_MAX_OPENED", "100")), 1);
    if( nOGRVRTLayerCount > nMaxSimultaneouslyOpened )
        poLayerPool = new OGRLayerPool(nMaxSimultaneouslyOpened);

    // Apply any dataset level metadata.
    oMDMD.XMLInit(psVRTDSXML, TRUE);

    // Look for layers.
    for( CPLXMLNode *psLTree = psVRTDSXML->psChild; psLTree != nullptr;
         psLTree = psLTree->psNext )
    {
        if( psLTree->eType != CXT_Element )
            continue;

        // Create the layer object.
        OGRLayer *poLayer = InstantiateLayer(psLTree, osVRTDirectory, bUpdate);
        if( poLayer == nullptr )
            continue;

        // Add layer to data source layer list.
        nLayers++;
        papoLayers = static_cast<OGRLayer **>(
            CPLRealloc(papoLayers, sizeof(OGRLayer *) * nLayers));
        papoLayers[nLayers - 1] = poLayer;

        paeLayerType = static_cast<OGRLayerType *>(
            CPLRealloc(paeLayerType, sizeof(int) * nLayers));
        if( poLayerPool != nullptr && EQUAL(psLTree->pszValue, "OGRVRTLayer") )
        {
            paeLayerType[nLayers - 1] = OGR_VRT_PROXIED_LAYER;
        }
        else if( EQUAL(psLTree->pszValue, "OGRVRTLayer") )
        {
            paeLayerType[nLayers - 1] = OGR_VRT_LAYER;
        }
        else
        {
            paeLayerType[nLayers - 1] = OGR_VRT_OTHER_LAYER;
        }
    }

    return true;
}